Sioux City, IA
Iowa · Records since 1889–2026
Records for August 11
🔥 Record High
August 11, 1935
+18° from 83° normal❄ Record Low
August 11, 1902
-16° from 62° normalAll-Time Records — Sioux City
Top 10 Record Highs — August 11
| # | Temp | Date |
|---|---|---|
| 🏆 | 101°F | August 11, 1935 |
| 2 | 100°F | August 11, 1947 |
| 3 | 97°F | August 11, 1988 |
| 4 | 96°F | August 11, 1936 |
| 5 | 95°F | August 11, 1995 |
| 6 | 95°F | August 11, 1933 |
| 7 | 95°F | August 11, 1905 |
| 8 | 94°F | August 11, 2010 |
| 9 | 94°F | August 11, 1949 |
| 10 | 94°F | August 11, 1941 |
Top 5 Record Lows — August 11
| # | Temp | Date |
|---|---|---|
| 🥶 | 46°F | August 11, 1902 |
| 2 | 49°F | August 11, 2012 |
| 3 | 49°F | August 11, 2004 |
| 4 | 49°F | August 11, 1982 |
| 5 | 49°F | August 11, 1903 |
Heat Wave Summary — Sioux City
threshold: 94°F (90th percentile of historical Jun–Aug highs)2026 Daily High Temperature vs Normal
Year to date144 of 222 days with data were above the 1991–2020 normal high for their date.
Days ≥ 90°F Per Year
1889–2026Average Daily High by Decade
Full year · complete decades only
Longest Heat Waves — Sioux City
| # | Dates | Days | Peak | Avg High | Avg Overnight Low |
|---|---|---|---|---|---|
| 🏆 | Jul 9, 1901 – Jul 27, 1901 | 19 | 106°F (Jul 21) | 100°F | 73°F |
| 2 | Jul 3, 1936 – Jul 19, 1936 | 17 | 111°F (Jul 4) | 104°F | 78°F |
| 3 | Jul 25, 1955 – Aug 5, 1955 | 12 | 107°F (Jul 31) | 100°F | 74°F |
| 4 | Aug 8, 1936 – Aug 18, 1936 | 11 | 105°F (Aug 15) | 99°F | 74°F |
| 5 | Jul 16, 1934 – Jul 25, 1934 | 10 | 107°F (Jul 20) | 102°F | 76°F |
| 6 | Jul 17, 1974 – Jul 26, 1974 | 10 | 103°F (Jul 18) | 99°F | 72°F |
| 7 | Jun 25, 1990 – Jul 3, 1990 | 9 | 104°F (Jul 3) | 96°F | 72°F |
| 8 | Jul 2, 1937 – Jul 10, 1937 | 9 | 103°F (Jul 7) | 97°F | 72°F |
| 9 | Jul 21, 1936 – Jul 28, 1936 | 8 | 108°F (Jul 25) | 101°F | 74°F |
| 10 | Jul 17, 1940 – Jul 24, 1940 | 8 | 107°F (Jul 24) | 100°F | 73°F |
Heat Waves Per Year
Warm Summer Nights (Jun–Aug)
Nights where the overnight low exceeded the 1991–2020 normal low
Above-Normal Summer Nights Per Year
Average June–August Low by Decade
Overnight lows · complete decades only
Precipitation
Actual vs. 1991–2020 full-month and full-season normals
Monthly Precipitation — Last 24 Months
Blue = actual · dashed line = monthly normal
Annual Precipitation Per Year (1970–2026)
Blue = above average · tan = below average · gold = 2026 (partial)
Heavy Rain Days Per Year (≥ 1.0")
Compare year-to-year changes in days with heavy rainfall (≥ 1.0")
Month in Review — July 2026
Average temperature · July 2026
41st-warmest month on record
33rd-warmest July of 138 on record
+2.6° vs. 74.7° average (1991–2020)Longest 90°F Streak in July
7 consecutive days with highs of at least 90°F (Jul 14–20, 2026, peaking at 101°F)
Ties the longest July streak since 2022 (4 years). The July record is 27 days, set in 1936.
100°F Milestone
Sioux City reached 101°F in 2026 — the first time it hit 100°F since 2023 (3 years).
Average July Temperature by Year
1889–2026 · 2026 highlighted
Warmest Julys on Record
| # | Year | Avg Temp |
|---|---|---|
| 1 | 1936 | 87.2°F |
| 2 | 1935 | 82.9°F |
| 3 | 1901 | 82.7°F |
| 4 | 1955 | 81.5°F |
| 5 | 1974 | 81.3°F |
| 6 | 1916 | 81.1°F |
| 7 | 1930 | 80.5°F |
| 8 | 1934 | 80.3°F |
| 9 | 2011 | 80.3°F |
| 10 | 2012 | 80.3°F |
Warmest Months on Record (Any Month)
| # | Month | Avg Temp |
|---|---|---|
| 1 | July 1936 | 87.2°F |
| 2 | July 1935 | 82.9°F |
| 3 | July 1901 | 82.7°F |
| 4 | July 1955 | 81.5°F |
| 5 | July 1974 | 81.3°F |
| 6 | July 1916 | 81.1°F |
| 7 | August 1936 | 81.0°F |
| 8 | August 1983 | 80.9°F |
| 9 | August 1947 | 80.7°F |
| 10 | July 1930 | 80.5°F |
Nearby Stations — July 2026
How the same month ranked at the closest reporting stations
| Station | Avg Temp | July Rank |
|---|---|---|
| Sioux City, IA | 77.3°F | 33rd of 138 |
| Norfolk, NE | 78.7°F | 18th of 128 |
| Sioux Falls, SD | 77.1°F | 19th of 134 |
| Spencer, IA | 74.1°F | 47th of 110 |
| Omaha, NE | 80.4°F | 16th of 156 |